1. Field of the Invention
The present invention relates generally to the art of electronic devices and, in particular, to a circuit board and a power source management system of a circuit board.
2. Description of the Related Art
The technology of Dynamic Voltage and Frequency Scaling (DVFS) is often used in a circuit board of an electronic device, such as a microcomputer, to improve system performance and decrease system power consumption. Specifically, the processor of the circuit board (such as a GPU of a graphics card) forecasts the performance that the system will require during the following period based on the current load, thus determines a required frequency and calculates a new voltage based on the new frequency. The processor informs the voltage regulating member so that the new voltage is provided to the processor from the voltage regulating member. The frequency regulation is performed by the processor itself, while for the voltage regulation, it is required that the processor provides a signal related to a desired core voltage to the voltage regulating member, and the voltage regulating member provides a core voltage to the processor based on the signal.
Specially, taking a GPU as an example, as shown in FIG. 1, a GPU 1′ is connected with a voltage regulating member 2′ via a parallel bus or a serial bus. The GPU 1′ outputs a signal related to a desired core voltage to the voltage regulating member 2′ through the bus connection. The reference voltage setting module 26′ of the voltage regulating member receives the signal, converts it to the desired core voltage Vn of the GPU and outputs it to the controller 24′ of the voltage regulating member. The setting terminal of the controller receive the above mentioned desired core voltage Vn, while the detecting terminal of the controller receive the core voltage Vc of the GPU to form a closed-loop control. The controller adjusts the output voltage Vcc based on the desired core voltage Vn and the core voltage Vc received by the detecting terminal until the core voltage Vc is equal to the desired core voltage Vn.
Since a parallel bus or a serial bus is required for the connection between the processor and the voltage regulating member, the complexity of the circuit board is increased. Meanwhile, the time for closed-loop regulation of the core voltage of the processor is extended because of the bus communication, thus the transient performance of the system is hard to be improved.
Therefore, there is a need of providing a circuit board and a power source management system of a circuit board to solve the above problem in the prior art.